wine and sparkling wine

Wine

Wine is the totally or partially fermented juice of fresh grapes. We differentiate between white, red and rosé wine. White wine is made from green grapes (sometimes also called white grapes), rosé and red wines from red or purple grapes.

Wine was grown in Egypt and the Middle East as early as 3500 b.c. and from about 1000 b.c. in the Mediterranean area. Beginning about 50 b.c., the Romans carried the cultivation of wine to other parts of Europe, namely France, Burgundy, Britain and Germany.

Production

1) Harvest

There are a number of terms associated with this subject which frequently appear in the trade literature, but also on bottle labels, and should therefore be explained briefly as follows:

* Hauptlese: This is the main harvest from which the most wine is produced. Table wines and quality wines are usually made from the Hauptlese. * Spätlese: This is the late harvest of the fully ripened grapes, which takes place after the Hauptlese. * Auslese: This term means ‘selection’ and is used for the especially choice and mature grapes from the Spätlese and the wines made from them. * Kabinett: Kabinett wines are those made from grapes from the Spätlese that are left over after the selection for the Auslese is finished. * Beerenauslese: When the grapes remain on the vine until they are overripe or noble rot has begun and are then harvested, this is termed the Beerenauslese. The grapes must be harvested by hand, which makes the wine expensive. * Trockenbeerenauslese: When the grapes remain on the vine until they are shrivelled and have noble rot they can be used to press the Tockenbeerenauslese. If no noble rot has occurred owing to unusual weather conditions or because of special characteristics of the variety, grapes that are mature and shrivelled are sufficient. Noble rot originates from a particular mould, Botrytis cinerea, which is either sprayed on the grapes or naturally occurs from spores in the environment. The spores then penetrate the grape skin and make it porous, so that water can escape and the sugar becomes very concentrated. The costly production process, the very small yield from the dried grapes, the long maturation that is necessary, and above all the marvellous aroma with little alcohol, fine sugar and a nice acidity make the Trockenbeerenauslese very expensive. On the other hand, these wines have an extremely long shelf life. * Eiswein: For ice wine the grapes are not harvested until they are frozen. They are pressed right in the vineyard while still frozen. The residual sugar content is very large. Eiswein is always a quality wine, but particular taste properties like those of the Trockenbeerenauslese are difficult to find. The risk associated with the production of Eiswein is quite large: If temperatures are moderate in the fall and winter, entire harvests may have to be discarded.

2) Mashing, pressing and fermentation

A) White wineWhite or ripe green grapes, and in some cases red grapes, are used to make white wine. They are crushed or mashed carefully, in order not to destroy the seeds, directly after the harvest. Then the juice (must) is separated from the skins and seeds (pomace) by pressing. The pomace contains tannins which are responsible for a bitter taste. The must is filled into tanks or wooden barrels, in which the primary fermentation takes place at about 13°C within approximately one week. In some cases the grapes themselves have sufficient wild yeasts that activate this process, but selected cultured yeast is frequently added. During fermentation, the sugar is converted to alcohol and carbon dioxide. The latter must be able to escape so that no excess pressure builds up. Must that is still fermenting and still contains yeast and sugar may be sold as Federweißer, or new wine. Fermentation stops by itself when no more sugar is available that the yeasts can convert or when the alcohol content exceeds 15% vol. This inhibits the growth of the yeasts. If fermentation is prematurely interrupted the result is wine with residual sweetness or sweet reserve. Following the primary fermentation, the yeasts are filtered out and the wine undergoes a second fermentation in barrels. This is when the bouquet and the nose develop, i.e., the typical flavour and aroma characteristic ofr a given wine. For a sweet wine, the sweet reserve is separated from the must prior to the second fermentation and is added to it again afterwards. The wine is stored in (sulphurized) ageing barrels until it can be bottled. If necessary, it undergoes so-called cellar treatments (see below) in the bottles.

B) Red wine Traditionally, to make red wine the mash is not pressed right away. Rather, it is first fermented along with the stems and seeds for 6–8 days at about 20°C in open containers (mash fermentation). Together with the enzymes, the alcohol that forms extracts the red pigment and the tannins from the skins. A so-called cap forms on the surface during fermentation, consisting of the seeds, stems and skins of the grapes, which needs to be punched down often to extract as much of the pigment as possible from the skins. Only then is the must pressed. The very large portion of tannins makes it possible to store red wine produced in this way for a long time; however, it also makes the wine quite sour, tart and astringent. The desired wine aroma, that is the scent and the flavour, forms only with long storage in the barrel and in the bottle. With some wines this can take a few months, with others a number of years.

In order to shorten the process, some vintners today use several other methods to extract the pigment from the skins: With thermovinification, the unfermented mash is heated to 40–50°C and special enzymes are added. In only 2–4 hours these extract sufficient pigment from the grape skins that the mash can be pressed. The huge amount of time saved makes the cost of production much cheaper. Moreover, fewer tannins form, which makes the wine milder than those produced in the traditional way. However, since the aroma has less time to develop, it is frequently less pronounced, and the storage life is reduced. A third method of making red wine, or of extracting the pigment from the skins, is the so-called carbon dioxide mashing. Here, the whole, uncrushed grapes are put into a closed container that is filled with carbon dioxide (CO2). Now fermentation takes place inside the grapes. As with thermovinification, fewer tannins are formed with this process, so that the wine is ready to drink more quickly and has a dark colour but is mild and aromatic in flavour. Unfortunately, it can also not be stored as long as traditionally produced red wine.

While must obtained both by the traditional process and by carbon dioxide mashing is already fermented and need undergo only cellar treatments as desired (see below), storage when necessary (following mash fermentation), and bottling, must from thermovinification still needs to be fermented. This takes place similar to white wine fermentation: The must is filled into tanks or wooden barrels where it undergoes primary fermentation at about 13°C within about one week. In some cases the grapes themselves have sufficient wild yeasts that activate this process, but selected cultured yeast is frequently added. During fermentation, the sugar is converted to alcohol and carbon dioxide. The latter must be able to escape so that no excess pressure builds up. Must that is still fermenting and still contains yeast and sugar may be sold as Federweißer, or new wine. Fermentation stops by itself when no more sugar is available that the yeasts can convert or when the alcohol content exceeds 15% vol. This inhibits the growth of the yeasts. If fermentation is prematurely interrupted the result is wine with residual sweetness or sweet reserve. Following the primary fermentation, the yeasts are filtered out and the wine undergoes a second fermentation in barrels. This is when the bouquet and the nose develop, i.e., the typical flavour and aroma characteristic for a given wine. For a sweet wine, the sweet reserve is separated from the must prior to the second fermentation and is added to it again afterwards. The wine is stored in (sulphurized) ageing barrels until it can be bottled. If necessary, it undergoes so-called cellar treatments (see below) in the bottles.

C) Rosé wine The same dark juice is used for rosé wine as for red wine, but in contrast to red wine, the step by which the red pigment is extracted from the skins is dispensed with. (More on this can be found under ‘Red wine’.)

D) Rotling/Schiller wine/Badisch Rotgold These wines are produced when white and red grapes are processed together. At the latest, they must be mixed when it comes to pressing. In contrast to all other wines, red or white must may be added to increase the residual sugar content.

Cellar treatments: enrichment, blending, sulphurization

Enrichment: This is also known as enhancement or chaptalization. It refers to the practice of enriching the must (not the finished wine) in a cool atmosphere with sugar or concentrated grape must in order to obtain more alcohol during fermentation. At cool temperatures, grapes develop less of their own sugar that can be converted to alcohol by the yeasts. With the help of chaptalization, the content can be increased up to 2% vol. The flavour is less sweet; we speak of ‘sustained’[MS1] . In Germany chaptalization is common, but for special quality wines it is not allowed. Nevertheless, it is employed worldwide and almost always with Beaujolais and Burgundy. When one speaks in warmer countries of improvement, this usually means the addition of tartaric acid to improve the flavour of the usually sweet wines, low in acidity, that come from there.

Blending: In order to obtain a brand wine with a flavour that is consistently the same, which many consumers today want, wines of different vintages, varieties and vineyards are frequently blended. This means that these different wines are mixed. This is not allowed without restrictions, however; In Germany red and white wines may not be blended. Some well-known wines are always blends: for instance, Chateauneuf-du-Pape in France consists of 13 varieties of grape, and a certain amount of white wine is added to Chianti in Italy.

Clarification, fining: By filtration or with the help of additives such as gelatine, kaolin, isinglass, or bentonite, gross turbidities can be eliminated. The surfaces of such materials can absorb suspended solids and colloids; they settle to the bottom and can be filtered out. Aberrations in colour (shades of brown) can be corrected with activated charcoal. These treatments are all part of clarification. Turbidity caused by certain metal ions such as iron, copper and zinc can be counteracted with blue fining, by which potassium ferrocyanide is added to the wine, converting the existing iron into Prussian blue and at the same time binding stubborn turbidities caused by proteins. The blue clouding substance that is formed within a few weeks settles to the bottom and can be filtered out. The use of too much potassium ferrocyanide (over-fining) can produce toxic hydrocyanic acid, however. Fining serves to clarify and improve the flavour of wine.

Sulphurization: To stabilize the colour, wine is frequently sulphurized; sulphur dioxide is added to the fermented wine. The sulphur reacts with the oxygen contained in the wine and in the ambient air and prevents the oxygen from reacting with and changing the pigments. However, sulphur dioxide also imparts an unpleasant smell as of ignited matches. With regard to the health risks, please read about Ingredients and Health Aspects below.

Acidulation: Particularly in warmer countries, tartaric acid is frequently added to finished wines to round out their sweet flavour and make them more palatable. The addition of tartaric acid to fresh grapes, grape must, partially fermented must and young wine is allowed to a maximum quantity of 1.5 g per litre; up to 2.5 g per litre is allowed to be added to finished wine. In addition, maximally 1 g of citric acid may be added per litre of finished wine to improve the maturation of the flavour.

De-acidification: Acid can be removed from sour wines to improve their flavour. In some cases this is necessary with wines that have been grown and pressed in northern areas and is allowed up to an amount of 1 g tartaric acid per litre.

Varietal wines are pressed from only one particular grape variety, after which they are then named. They taste consistently similar, no matter where they have been produced, since they should have the characteristics typical for the variety (e.g. Riesling).

Single-site wines, or estate wines, are those that grow and are pressed in given regions and that emphasize the distinctive features typical of the region (e.g. sherry).

Brand wines are usually produced by blending and have an invented brand name (e.g. Blanchet).

Blends are wines that are produced by mixing various wines or grape varieties. In addition to the high-quality brand wines, cheap table wines are made by blending wines from different regions.

Piquettes are made from the pomace, i.e. the lees after pressing. They are sourer and more bitter than wines made from must and may not be sold. Therefore, they are made only for one’s own use.

Designations of taste

A sweet wine has a very high residual sugar content of at least 45 g per litre. The terms medium sweet and medium dry describe either wines that are not totally fermented or wines to which sugar or – more frequently – pasteurized, unfermented must from the same harvest (sweet reserve) has been added following fermentation. In order to obtain medium-sweet or medium-dry wines the fermentation must be stopped prematurely. This is achieved with cold (inhibits the growth of yeasts), with heat (likewise inhibits the yeast growth), or with filtration. These are the traditional processes, while the addition of must or sugar is more modern and more controversial. It is clear, however, that they produce more digestible wines, since less sulphur dioxide is needed to stabilize them. A wine is considered dry when it is totally fermented and contains no more residual sweetness.

Depending on the country of origin (France, Italy, Spain or Germany), alternative terms for ‘sweet’ are doux, dolce, dulce or süß; for ‘medium sweet’ moelleux, amabile, semidulce and lieblich are used. ‘Medium dry’ wines are known as demi-sec, abboccato, semiseco and halbtrocken, while ‘dry’ are called sec, secco/asciutto, seco, and trocken.

Quality factors and categories A great many factors affect the flavour and the quality of a wine, beginning with such obvious ones as the variety of grape, sunlight and blend and continuing with composition of the soil, vintage and storage. The most important of these factors are discussed below.

Grape variety: Each variety of grape develops different proportions of the ingredients. Of particular importance in this respect are sugar content, acidity, aromatic substances and tannins. Accordingly, the wine produced from it has a characteristic aroma. Some grape varieties are known for their special quality, which is often evident only in certain areas of cultivation; others are popular because they have a dependably high yield.

Area of cultivation: In fundamentally cooler regions the grapes produce less sugar; correspondingly, the wine tastes less sweet as long as no sweet reserve is added. In other regions, the same variety of grape can produce a different wine, because thanks to more sunlight a higher level of sugar develops, and perhaps less acidity. For this reason, some varieties yield good qualities only in certain areas of cultivation (e.g. Silvaner in France).

Site and soil: The site is related to the area of cultivation; frequently, the site also describes the area of cultivation, in this case meaning the location of the vineyard or hillside in the region. Important factors are the angle in relation to the sun, the nature and condition of the soil, its colonization with micro-organisms and its capacity to store water and heat, and the particular climate, (fog, frost, humidity). All of these factors can influence the quality of the wine to a certain extent.

Cellaring / vinification: Even the best grapes do not necessarily yield a top wine. The treatment during and following the harvest is just as crucial as the variety and the growing region. On the other hand, by the way in which he handles the grapes, a good vintner can produce a relatively good wine from an intrinsically poor grape. To this end he has a number of techniques at his disposal: enrichment, acidulation, de-acidification, clarification, sulphurization and blending.

The quality is determined not only according to sensory criteria (smell, taste, appearance, mouthfeel), even if at least all wines produced in the EU (with the exception of table wines) must pass a sensory and analytical test. Quality grading complies with fixed parameters that are found in the German Wine Law and Wine Regulation. Other regulations apply in other European and non-European countries, however, so that the wines of a given quality category are comparable to only a limited extent.

The primary determinant of the quality of a wine in Germany is the so-called must weight, or the specific mass of the must, which includes the sugar and extract content of the grapes and thus enables conclusions to be drawn as to the degree of maturity. This is measured in degrees Oechsle. The Oechsle degrees indicate how many grams more a litre of must weighs than a litre of water. The higher the degree value, the better the quality.

For quality wine psr (produced in specified regions – German Q.b.A.) the corresponding geographical origin is indicated. Higher requirements are made of its must quality than for table wines, although enrichment, acidulation or de-acidification are still allowed. Quality wines psr from different German areas of cultivation may be blended and still sold as such. In such cases, however, they must then carry fantasy names instead of the designation of origin.

A special quality wine, or quality wine with predicate (German Prädikatswein), is likewise a quality wine psr but it fulfils stricter criteria: It may not be enriched; moreover, the natural minimum alcohol content must be more than 8.5% vol. for Kabinett and Spätlese and the real alcoholic strength by volume more than 7%. This must be a minimum of 5.5% vol. for the predicates Beerenauslese, Trockenbeerenauslese and Eiswein. While Spätlese, Auslese, Beerenauslese, Trockenbeerenauslese and Eiswein must fulfil stricter criteria than Kabinett right from the harvest, Kabinett wine may be bottled and shipped at the earliest after January 1 of the year following the harvest.

Table wine, including country wine: The grape varieties for table wines must be approved or recommended. The minimum alcohol content is 5 g/l, or 5% vol. Table wine may be enriched and also concentrated. Even a blend of different grape varieties is allowed, and this even from different countries in the European Community, as long as the major portion is at least 75% of the total. Better-quality table wines may be designated as country wines. To this end the grapes must be from specified regions and the wine may not be concentrated. The natural minimum alcohol content must be 0.5% vol. greater than that of the corresponding table wine. While table wine has a negative connotation in Germany because merchants and consumers adjudge it to be of poor quality, the French and the Italians see no qualitative disadvantages in table wine.

Sparkling wine

Production

Sparkling wine and champagne are made from finished, healthy, non-sulphurized, very acidic, wines poor in minerals whose alcohol content is not above 11% vol. and that contain no preservatives. After fermentation is finished, sugar and yeasts are added again to bring about a new fermentation during which more alcohol and CO2 are formed. This would normally escape, as with the production of wine. Carbon dioxide dissolves and remains dissolved only under very great pressure and in a closed container. Therefore, the containers must be kept tightly closed. Sparkling wine cannot mature in wine bottles because these do not withstand the developing pressure of about 6 bar. Special bottles for sparkling wine are necessary. Many wine producers let sparkling wine mature in gas tanks and bottle it only afterwards. This does not necessarily have a negative effect on the quality, which depends rather on the base wine. To ensure optimal conditions for the yeast to work a constant temperature of at least 15°, even better 20°C, should be maintained.

In order that the yeasts are in constant contact with the sugar molecules, the bottles or tanks must undergo regular riddling (remuage). This can be done (several times daily) by hand or on so-called mechanized gyro palettes. The fermentation begins after 2–5 days and takes 6–8 weeks, during which the bottles must continue to be riddled. Thereafter, the sugar is fermented and the contents of alcohol and CO2 are set.

Now the yeasts must be removed from the bottle or the tank. With the tank, the sparkling wine can simply be drained, with attention being paid to keeping the yeasts in the container. With bottles there are two possible methods: 1) During fermentation and riddling the bottles are rotated a bit every day, such that at the end of these processes they are upside down and the yeast has settled on the cork. The necks of the bottles are submerged with the opening downwards in a -15° to-25°C saltwater bath so that the yeast plug freezes and can be removed. 2) Following fermentation, the bottles are stored in a cool place with their openings pointing down and are rotated with a jerk daily, along their longitudinal axis, causing the yeast to slide towards the cork. After several days, the plug can be frozen and removed as described above.

While the yeast is in the sparkling wine, other important ingredients also develop, such as amino acids, vitamins and flavours. For this reason, some companies leave the sparkling wine in the bottles with the yeasts for several months and disgorge them shortly before they are shipped.

Designations of tasteLike wines, sparkling wines are also classified by taste according to their residual sugar content. Sparkling wines with little residual sweetness (up to 15 g sugar per litre) are termed dry. The international designation is brut. Very dry sparkling wines have 12–20 g sugar per litre and are called extra dry.Dry and sec are the international designations for dry sparkling wine or champagne with 17–35 g sugar per litre.Medium dry or semi sec sparkling wines contain 33–50 g sugar per litre, while sweet products, also called mild, have a residual sweetness of over 50 g per litre.

Champagne

Champagne is an especially fine sparkling wine made of grapes from one certain small area of cultivation in France, la Champagne. Non-sparkling champagne (i.e. wine) has been produced for centuries, but it was the Benedictine monk Dom Perignon (1639–1715) who discovered the process for producing sparkling wine.

Ingredients and health aspects of wine and sparkling wine Paracelsus, a great physician of the Middle Ages (1493–1541), is credited with the knowledge that “All things are poison and nothing is without poison; only the dose makes a thing not a poison.” This also applies to wine, to which both positive and negative health effects can be attributed. On the positive side are the effects of the fruit acids, which in nature determine the resistance of the grapes against diseases and pests. They detoxify to a certain degree and thus counteract some infectious diseases. Together with the alcohol, the fruit acids inhibit the growth of viruses and bacteria and kill their germs. In addition, they stimulate the secretion of gastrointestinal fluids and the digestion.

The alcohol content must be seen in a more critical light. From a nutritional point of view, alcohol is a poison. It leads to an unbalanced and excessive supply of energy and can – if one consumes it regularly in large amounts – give rise to liver damage, inflammation of the gastric mucosa, nerve damage and psychological problems. There is danger of addiction. Alcohol can be degraded by the human body, but only in certain amounts: For men, 50–80 ml pure alcohol daily, for women 25–50 ml, are not a problem from a medical point of view. Those who regularly consume more are considered to be addicted to alcohol. It should be noted, however, that just a half litre of wine contains 40 ml of alcohol. Basically, the span of time over which the alcohol is consumed is also important: A large amount of alcohol within a short period of time leads to a great burden on the liver and possibly also to liver damage, while the same amount spread over an entire day is less damaging, because the alcohol is slowly but continuously degraded.

Sulphurized wines are not unproblematic for everyone. Sensitive persons develop headaches after consuming even small amounts. Sulphur dioxide must be degraded quickly in the human body so that it cannot combine with amino acids, proteins and other substances and thus disturb a very sensitive balance. The usual reactions to an excessive amount of sulphur are of a pseudoallergic nature. Asthmatics in particular should be very careful in this regard. In some cases only rigorous abstinence from all sulphurized products will help.

Biogenic amines are compounds that are formed during digestion through the degradation of protein building blocks, such as amino acids, and that can have various unpleasant consequences for the body. High doses are harmful to everyone’s health; however, some people react more sensitively than others to biogenic amines and are more likely to present with the typical ailments, among them migraine and allergic reactions. Many must even take strict care to ensure that they do not ingest any products that contain such substances or that could stimulate their formation in the body. As the production of wine involves the use of micro-organisms, namely yeasts, that convert sugar to alcohol and carbon dioxide, biogenic amines are formed here as well. The best-known and most important in this case are histamine, tyramine and serotonin, but another 22 biogenic amines have also been verified in wine. Histamine is the amine most worrying for human health. In small doses it triggers headaches; other symptoms are diarrhoea, allergic skin reactions, facial swelling, general signs of food poisoning, and a sharp drop in blood pressure. In extreme cases histamine can even produce a state of shock. Luckily, most symptoms subside after some time and have no after-effects. Dangerous above all are the fluctuations in blood pressure, particularly for elderly people or persons with heart problems. The ‘hangover' that follows the consumption of alcohol is attributed at least partially to histamine. The histamine contents of wine fluctuate. With pure starter cultures (i.e. special yeast cultures) and good hygiene in the wine cellar the development of histamine can be almost completely prevented, however. Bentonite and activated carbon can filter the substance out of the wine, and high sulphurization also achieves low contents of histamine, whereby sulphurization also has unpleasant consequences for some people (see above). The following limit values for histamine apply in Germany and the European Union: maximally 100–200 mg per kilogram food product. The toxic dose for most people fluctuates between 100 and 1000 mg; wines contain about 4 mg per litre. Tyramine is usually tolerated without any problems by people with a healthy metabolism. The toxic doses is between 25 and 250 mg; however, the amount of tyramine in wine is also less than that of histamine. Typical signs of tyramine poisoning are high blood pressure, piercing headaches that appear only several hours later and do not subside in some cases until 8–24 hours thereafter, dizziness, disturbed vision, hypersensitivity to light, noise, smells and sounds, pallor of the forehead, nausea, diarrhoea and vomiting. The symptoms usually abate following a long sleep, and serious after-effects are rare. Tyramine is a concern only when hypertensive medications are taken at the same time.

Vegetable tannins are bitter-tasting and have an astringent effect by which they protect themselves from herbivores. They are not themselves unhealthy, but they can cause flatulence and inhibit the resorption of certain medicines by the gastric mucosa and the resorption of iron. Tannins are found in grapes, especially in the stems, skins and seeds, and get into the wine via the mash. Thus, they play a greater role with red wines than with white wines, as for the latter seeds, skins and stems are completely separated, while the complete chopped grapes are mashed to produce red wine in order to release the red pigment from the skins (see above).

* n.a. = no data available ** Heavy wines contain more alcohol than light wines: 1 g alcohol accounts for 7 kcal, so that the amount of energy increases with an increased alcohol content.

Tips on storage and care

Wines that are sealed with natural corks must be stored horizontally. This is important to ensure that the cork doesn’t dry out and contract, no longer providing an airtight seal.

Wines that contain more alcohol (dessert wines) can corrode the cork, however, and should be stored vertically. Sparkling wine and champagne should be drunk soon after they are produced or bought, since the carbon dioxide continually escapes and the quality deteriorates.

Storage in a cool, dark place is recommended for all wines. White wines are optimally stored at 8°–12°C, red wines at 14°–18°C and dessert wines at 10°–18°C. The same applies for sparkling wines. Higher storage temperatures and especially sunlight can cause reductions in quality and thus a loss in value. In contrast, lower storage temperatures carry the risk of precipitation of proteins, dyes and tartar.

Only wines that are already of good quality, heavy, rich in alcohol, and acidic can improve with long storage. An example would be the Trockenbeerenauslesen. Less acidic wines with less alcohol should be drunk fresh. Their quality diminishes over time. Normal white wines, for instance, taste really good for only 1–2 years. Red wines contain more acid and tannins and in principle can therefore be stored longer than white wines.

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